An electrostatic capacitance sensor which detects the position or the motion of a detection object based on a change of an electrostatic capacitance is known. The electrostatic capacitance sensor includes one or multiple electrodes for detecting. When the detection object approaches the electrodes for detecting, a capacitance value of the electrostatic capacitance generated between the electrodes or between the electrode and a ground is changed. The electrostatic capacitance sensor is a device which detects a motion of the detection object by measuring a change of capacitance value as an electrical signal.
In JP 2011-252881A (Reference 1), a sensor module for controlling an automatic door is disclosed which makes the automatic door opened when a motion of a detection target body (user's hand, or the like) detected by the electrostatic capacitance sensor coincides with a predetermined motion pattern.
The electrostatic capacitance sensor described above can be used for an operation of detecting an opening and closing body for a vehicle (sliding door, back door, or the like) supporting to automatic opening and closing. Such an opening and closing body for a vehicle performs an opening and closing operation or is stopped by an operation of the user. Accordingly, the user may perform the operation while the opening and closing body is in motion. For example, it is assumed that an operation for emergency stop should be performed when an object is about to be caught in the opening and closing body, or when the opening and closing body is about to hit a wall. When a sensor module disclosed in Reference 1 which detects the motion of the detection target body is applied to the opening and closing body for a vehicle supporting to such an operation, there is a problem in that an operation procedure is complicated and the operation takes a long time. For this reason, there is a case in which the operation for emergency stop cannot be performed in a short time while the opening and closing body is in motion.